The workshop will NOT start at a fixed time you can come any time between 12:00 and 17:00 on the 27th.
The workshop will take place at the c3RE facilities (a subassembly of the ChaosWest assembly) here https://35c3.c3nav.de/l/c:0:445.37:160.31/details/

Another important information for Mac users: By now we are not able to get the project running with MacBooks.

Build your own yubikey - please don't expect too much because of the catchy
title. In this workshoup you will not be able to build a fully fledged yubikey
with tamperproof memory and a real smartcard and all that stuff. But you will
be able to build your own two-factor solution with a little USB-stick.

We ordered 100+ digistumps (small USB-Sticks with a programmable
microcontroller on it) and we have at least two firmwares ready to flash
(static-password and HOTP). In addition to that we have 3D-printed cases that
you can use as a surrounding for the digistump. The cases have a little hole at
the end so you can attach them easily to your keychain.

The static password-firmware can be used to store any password or key-sequence
you might need often.

The HTOP-firmware is able to store a secret which is used to derive HOTP-Tokens
from. With that you can, for example, unlock your KeePass. The HOTP-firmware
has been developed by some guys from the labor, bochum originally. If you choose the HOTP Firmware to unlock your Keepass the workshop will include a (beginners(as we would call ourselves beginners too)) introduction to HOTP as well.